Java 如何从一个字符串中随机输出字符呢？

实现思路:
    笔者将采用自定义的随机字符输出方法(非Collections.shuffle)方式
	具体步骤如下所示:
	 1.使用while循环遍历字符串
	 2.每次随机输出一个字符
	 3.然后删除已输出的字符

package com.java265.other;
import java.util.Arraylist;
import java.util.List;
public class Test14 {
	/** java265.com 示例 */
	public static void main(String[] args) {
		// 自定义随机字符串
		String str = "java265.com";
		for (int i = 0; i < 20; i++) {
			shuffle(str);
		}
	}

	public static void shuffle(String input) {
		List<Character> characters = new ArrayList<Character>();
		for (char c : input.toCharArray()) {
			characters.add(c);
		}
		StringBuilder output = new StringBuilder(input.length());
		while (characters.size() != 0) {
			int randPicker = (int) (Math.random() * characters.size());
			output.append(characters.remove(randPicker));
		}
		System.out.println(output.toString());
	}
}

------运行以上代码，将输出以下信息------
a.co652avjm
6m2a.ovjca5
j.oc2ava6m5
2aavjc56o.m
5vj.a6m2oac
.co56am2jav
covma52j6a.
.2mvjca5ao6
o65mvaa2.jc
v2c5a.oj6am
2ma5oj.6cva
a6o2mcaj5.v
a5.ca6voj2m
.2vj56acmoa
m.oj2ca56va
oaj6.a5v2mc
v.5jaco6ma2
cv5ja62.oam
o6aj.vmc52a
aa.mc2j56ov